T-048:
V3 C3 Lower bound confirmed
= 7.4, by Hosono's mixed rectangle-density certificate of 28 September 2026. It exceeds Green's reported 2 sqrt(2) + 101/25 + 3 sqrt(14)/25 = 7.3174260 by more than 0.0825739888. The certificate's mass is below 51 too, so it gives as well.
The certificate is a D4-expanded rectangle density of 553 orbit representatives, total mass 4999999/100000 < 50, core side 9977/10000 and 201 net half-angles of step 83/40000. It is accepted at every oblique net angle by code/mixed_rotated_verify.cpp, a research copy of Tokoharu's verify.cpp that accepts coverage at least 1 instead of 10001/10000 and checks each net node's unit-square centre domain, and at angle zero by exact integer tables.
The source's complete replay was run here on 29 September 2026 on the pinned bundle, with the source's driver and checker unchanged: all 201 directions, each equal to the shipped record. This repository's exact audit checked the premises and the integrity of all 621 bundle files and all 200 oblique inputs. The replay runs the source's own algorithm and is not an independent decision of coverage.
Hosono after Daniel and Tokoharu, square-packing-bounds, the measure resting on Tokoharu's format and checker. The source says parts of the work were produced with AI assistance under human direction.
Significance, composition and next rung
- Significance
- Raised the verified lower bound at by 0.317 over Nagamochi's closed form, and at by 0.236, and stands 0.0826 above Green's reported value at . The two changes to Tokoharu's checker were read and found legitimate on 2026-09-28. A substantive case result at S3. The closed form has been a reported bound since Karakuş's finding (T-085, merged 2026-10-03), so the margins over the verified floor it left, Karakuş's general bound, are larger. Confirmed on 11 October: the mixed certificate, point masses beside rectangle densities, is a kind within Tokoharu's framework, as T-073's linear measure is, and an extension at one count is S3 with the kind noted, as T-073 is; T-047, the framework, holds the S4.
- Composition
- One certificate. E-n050-wand125-mixed-740-source-replay replays it in full with the source's own driver and checker: one interval-certified method, replayed here, C3. Coverage is decided by the source's C++ checker alone, and the axis tables are a second implementation for one direction and not a second method. takes the same certificate directly, its mass being below 51, so no step is added.
- Next rung
- V4 and C4 need two adversarial AI reviews by distinct reviewers and a human oversight record; one adversarial review is retained. A second machine method would be a method-distinct decision of rotated coverage; the replay here runs the source's own checker. The checker's controls were made on the certificate of the same kind; devtools.audit_wand125_point_and_mixed mixed-control on this certificate would bind them to this measure as well.
- Novelty
- previously-published Present in an identified source
The cases
As published
Proven
- exact
Citation record n-050
lowerHosono after Daniel et al. 2026, GitHub (confirmed T-048)
upperSchadt 2025, Squares in Squares (reported)
Open
- optimality
The case record
Results on these cases
15 results in the register on , oldest first, each with what it established and how it stands now.
2005 published T-007 ·
for
V0 C1 Lower bound incomplete on these cases, superseded by T-048 and T-090
2026-09-04 published T-085 ·
Nagamochi 2005, Lemma 1 is false for every container with and
V3 C3 Correction confirmed
Karakuş; Vlasenko · Karakuş 2026 · chelokot Nagamochi counterexample 2026 · packet · register
2026-09-27 published T-046 ·
Rectangle-density lower bounds reported for 48 counts in
V0 C0 Lower bound recorded superseded by T-090
Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026 · wand125 rectangle bounds 2026-09-28 · packet · packet · register
2026-09-28 published T-048 this result ·
V3 C3 Lower bound confirmed
Hosono after Daniel, Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 point and mixed bounds 2026-09-28 · packet · source · review · register
2026-09-28 published T-070 ·
Rectangle-density lower bounds replayed at 25 counts in
V3 C3 Lower bound confirmed superseded by T-090
Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026-09-28 · packet · packet · source · review · register
2026-09-29 published T-058 ·
Rectangle-certificate ceiling
α·UB(n)proved for ..100;B·UB(n)on 64 grid rowsV3 C3 Method limit confirmed
Hosono after Tokoharu, Daniel · wand125 tools 2026 · packet · register
2026-09-29 published T-083 ·
for every nonsquare
V3 C3 Lower bound confirmed on these cases, superseded by T-048 and T-090
Karakuş · Karakuş 2026 · source · register
2026-10-03 published T-082 ·
Mixed rectangle-measure lower bounds verified at 22 counts in
V3 C3 Lower bound confirmed on these cases, superseded by T-090
Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds 2026-10-03 · packet · packet · source · review · register
2026-10-04 published T-090 ·
Mixed rectangle-measure lower bounds verified at 17 counts in
V3 C3 Lower bound confirmed
Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds 2026-10-04 · packet · source · review · register
2026-10-05 published T-101 ·
Exact certificates of 77 catalogue packings:
s(n) ≤ S',1.2e-16to9.8e-15above each sideV3 C3 Upper bound confirmed on these cases, superseded by T-126 and T-155
Daniel after Couzo, de Winter, Ellsworth, Levy · evand exact optima 2026-10-05 · packet · register
2026-10-08 published T-125 ·
Complete rational construction reports at 25 counts
V3 C3 Upper bound confirmed superseded by T-126
2026-10-08 published T-126 ·
Undilated n51 construction over Q(sqrt2)
V3 C3 Upper bound confirmed
2026-10-12 established T-155 ·
Exact regularized sides at 59 counts,
5.4e-20to9.9e-15below the ceilings they replaceV3 C3 Upper bound confirmed
2026-10-13 published T-180 ·
Closed-form lower bound for every non-square , reported
V0 C1 Lower bound reviewed on these cases, superseded by T-048 and T-090
Hosono · wand125 closed form 2026-10-14 · packet · packet · register
2026-10-16 published T-204 ·
Mixed rectangle-measure lower bound reported, on a 2,073-direction declared net
V0 C0 Lower bound recorded
Hosono after Tokoharu and Levy · wand125 fine-net lower bounds 2026-10-16 · packet · register
Links
- On this site
- Case record, · Frontier row, · Case record, · Frontier row, · T-048 in the results table
On GitHub, at main
- Register
- T-048 in
results.yaml, line 4271 - Evidence
E-n050-wand125-mixed-740-report·E-n050-wand125-mixed-740-source-replay- Proofs and certificates
- certificate
candidate.json.gz· proofcontinuous-density-certificate.ja.md· auditreview-2026-09-28-wand125-n50-mixed-verifier.md - Sources
- wand125 point and mixed bounds 2026-09-28 (its own site, retained copy)
- Source packet
resources/web/wand125-point-and-mixed-2026-09-28/README.md- Artifacts
13 artifacts and controls
resources/web/wand125-point-and-mixed-2026-09-28/README.mdresources/web/wand125-point-and-mixed-2026-09-28/square-packing-bounds/certificates/mixed_n50_L740/README.mdresources/web/wand125-point-and-mixed-2026-09-28/square-packing-bounds/certificates/mixed_n50_L740/code/mixed_rotated_verify.cppresources/web/wand125-point-and-mixed-2026-09-28/square-packing-bounds/certificates/mixed_n50_L740/completion-audit.jsonresources/web/wand125-point-and-mixed-2026-09-28/receipts/n50/bundle_check.jsonresources/web/wand125-point-and-mixed-2026-09-28/receipts/n50/sample.jsonresources/web/wand125-point-and-mixed-2026-09-28/receipts/n50/full/compare.jsonresources/web/wand125-point-and-mixed-2026-09-28/receipts/n50/full/run.logresources/web/wand125-point-and-mixed-2026-09-28/receipts/exact-audit.jsondevtools/audit_wand125_point_and_mixed.pydocs/project/reviews/review-2026-09-28-wand125-n50-mixed-verifier.mdtests/test_wand125_checker_controls.pyresources/web/wand125-point-and-mixed-2026-10-01/receipts/n37/control.json- Case file
frontier/n-050.md(verified lower, verified upper, reported lower, reported upper) ·frontier/n-051.md(verified lower, verified upper, reported lower, reported upper)